Lubricating oil composition containing phosphorus sulfide hydrocarbon reaction product



United States Patent Ofilice Patented Aug. 16, 1955 LUBRICATING OIL COIVHUSITION CONTAINING PHOSPHORUS SULFIDE HYDROCARBON REAC- TION PRODUCT Leonard E. Beare, Lansing, 111., assignor to Sinclair Refining Company, New York, N. Y., a corporation of Maine No Drawing. Application April 25, 1951, Serial No. 222,933

Claims. (Cl. 25246.6)

My invention relates to the manufacture of improved lubricating oils and more particularly relates to imparting extreme pressure properties to lubricating oil compositions in an improved manner. My invention provides an improved oil and phosphorus pentasulfide reaction product as a lubricating oil additive, an improved 1;:

manufacturing method to obtain the additive and lubrieating oil compositions containing the additive which possesses improved extreme pressure properties.

Many reaction products of many organic products of phosphorus, sulfur and chlorine compounds have been proposed and tried as lubricating oil extreme pressure additives. I have investigated a very great number of these products and the associated manufacturing prob lems. The specification requirements for gear oils are today so rigid that it is very difficult to find an extreme -i pressure additive which is non-corrosive, suitably compatible with the mineral oil base, which has the required extreme pressure capacities and yet which is low enough in cost that it can be added to the oils in the desired proportion without increasing excessively the cost of the oils. There do not appear to be any general rules distinguishing useful compositions from those lacking in practical utility. On the contrary, I have found that even apparently minor properties of the starting materials and seemingly unimportant conditions of manufacture are critical in producing additives of superior properties. Thus 1 have found that heavy mineral oil or bright stocks yield reaction products of special value when reacted with phosphorus pentasulfide under particular conditions of reaction and product work-up. I have found that reaction at about 400 to 500 F. for a period of about i0 to hours produces phosphorus and sulfur containing reaction products of higha ly useful properties from the extreme pressure standpoint. The proportion of phosphorus pentasulfide employed in the reaction should approximate 7 to 17 per cent and advantageously should be held within the range of 7 to 14 per cent for economy of operation and optimum yield of useful phosphorized product. The reaction mixture contains a number of insoluble reaction products which are oil insoluble or may be deleterious in the trial blends. It is essential that these materials be removed advantageously as by filtration or centrifugation. The separation should be performed at elevated temperature but advantageously after cooling to about 150 to 250 F. For a product of real value in lubricating oils, I also have found that it is then necessary to treat the reaction product by steam blowing until the product is substantially free of hydrogen sulfide. Only in this manner have I been able to obtain a phosphorus and sulfur reaction product which is stable, non-corrosive, clear and oil compatible. Prosludging and rusting components are largely eliminated, and the useful E. P. life of the blended oil compositions is enhanced.

Processing and equipment costs are minimized, while yields are greatly improved.

When the new additive is blended into mineral oils, it imparts in even very small concentrations extreme pressure capacities. Advantageously, the concentration in finished oils, e. g. gear oils, is within the range of about 1 to 6 per cent. The most useful oils however contain the additive in concentrations of about 2 to 4 per cent. In terms of phosphorus content, I have found about 0.03 to 0.06 weight per cent organically combined phosphorus particularly useful, depending upon the E. P. demand on the lubricant. The sulfur content appears to be negligible and is largely accounted for by organic by-products. The finished gear oils ordinarily contain in addition other chlorine and/or sulfur containing extreme pressure additives, such as chlorinated wax or chlorinated naphthalene, sulfurized sperm oil or sulfurized lard oil and other chlorine and sulfur containing hydrocarbon derivatives as well as other conventional lubricating oil additives, such as poor depressants, anti-foaming agents and the like.

Although other phosphorus reagents such as phosphorus chlorides or oxides have been employed to react with oils, 1 have found that phosphorus pentasulfide is by far the most satisfactory reagent to employ in preparing extreme pressure type compositions. The phosphorus sulfides and particularly phosphorus pentasulfides react with mineral oils to give many times greater yields of phosphorus containing compositions useful in improving the load carrying capacities of mineral oil blends. Thus a product prepared by reacting 44 parts of phosphorus trichloride with 356 parts of a bright stock at 150 to 180 F. for several hours and steam hydrolyzing gave a product which was not very dilferent from a suspension of phosphoric acid in oil. When the reaction conditions were modified to provide longer time at higher temperature in the presence of an alkylating catalyst, e. g., aluminum chloride, a product was obtained containing only 0.23 phosphorus and less than 0.05 per cent chlorine from 2700 parts of bright stock and 400 parts of phosphorus trichloride, reacted at 200 to 220 F. for 24 hours and steamed and clarified.

I also have found that it is important to employ a relatively heavy oil of high molecular weight range such as a bright stock, that is a residual lubricating oil stock, rather than lighter oils such as neutral oils or the usual lubricating oil distillate stocks, as a starting material. If the reaction is run on neutral oils, a large percentage of insolubles forms during the phosphorus sulfide reaction. After filtration, the liquid portion again forms additional large amounts of insolubles during steam treatment. Yields of phosphorus containing products amount to as little as 25 per cent based on the phosphorus sulfide used. By contrast, with bright stocks, insolubles formation is greatly reduced and the comparable yields of phosphorus containing products range from about to per cent. Moreover, the load capacity of the bright stock reaction products is superior to that of the neutral oil reaction products. For example, where additives prepared according to my invention from bright stocks consistently show less than 30 mgs. total Wear on the test cup and block in Timken L20 procedure #3 weed out tests (see below for test description) without burnish or score, comparative preparations using a neutral oil may show about 90 mgs. or more total wear with observable burnish and scoring. For best results it is advantageous to employ bright stocks having viscosities within the range of about to 300 SUS at 210 F.

Although reaction of phosphorus sulfides with oils commences at comparatively low temperatures, I have found that the temperature level during the reaction period is .of fundamental importance in determining yield and the nature of the reaction products. Thus phosphorus pentasulfide reacts with various brightls'tocks at about 320 F. Only about 2.5 to 7 per cent of phosphorus pentasulfide, however, is reacted in from 10 to 20 hours. The reaction products moreover'are not stable under steam treatment. Up to half of the phosphorus increase is hydrolyzed to oil insoluble phosphorus acids. The resulting composition contains an acid haze which is diificult to separate completely by filtering, settling or water washing. The traces of acid left in the composition are pro-rusting, procorrosive and pro-sludging. Reaction times up to 48 hours effect little improvement with respect to acid haze on steaming. Also, additional digestion at 320 F. after filtering out unreacted phosphorus pentasulfide or using a reduced amount of phosphorus pentasulfide such as 2.5 per cent for reaction times up to 72 hours does not eliminate the acid haze after steaming. Increase in the reaction temperature up to 360 F. also is ineifective. If the reaction is conducted at 400 to 500 F., however, the products are stable and show no separation of acid haze'dun'ng the steaming process. In addition, about 2 to 4 timesas much phosphorus pentasulfide reacts at 400 to. 500 F. so that the final product contains from 3 to 6 times as much oil soluble phosphorus in chemical combination as the low temperature: reacted materials.

The reason for the hydrolysis of the low temperature reaction products to insoluble acids during the steaming not understood. However, it appears that only one of the two available atoms of phosphorus in the molecule of phosphorus pentasulfide is directly alkylated, that is linked to. a carbon in a considerable portion of the low 7 temperature reaction products. The second atom of phosphorus is connected to the oil alkylated phosphorus atom only through a sulfur atom. The conditions of the steam treatment are suflicient to remove sulfur from phosphorus, and this action also releases phosphorus in the form of oil insoluble phosphorus acids. 7 When the oil-phosphorus peritasulfide product is formed at 400 to 500 F., both atoms of available phosphorus appear to be directly alkylated or linked to carbon atoms so that hydrolysis resulting in free inorganic phosphorus acids does not occur L under the conditions of steam treatment.

The reaction of the oil and phosphorus pentasulfide produces oil irisolubles. I have found that it is important to separate solidfrom liquid products at elevated temperature;-. g. 150 to 250 F., before thesteaming operation.

filtration before steaming. The former were uniformly 0 higher in per cent phosphorus but they were consistently more pro-sludging, showing as high as about 1 per cent sludge'andas high as 0.75 per cent tube deposits in sludge accumulation tests at 120 hours. The insolubles separation step appears to be more critical with the lighter stocks as the very heavy stocks form considerably less amount of insolubles during the phosphorus pentasulfide reaction,

Separation of the non-liquid products is much more difii- Gear Oil Proc. Tab. on do cult, at room temperature and removes a considerable amount of relatively low'solubility reactionproducts without any compensating improvement in the product. Sepa ration at reaction temperatures is mechanically more difiicult and less likely to remove all the undesirable components. Accordingly, I prefer to cool the reaction mixture without-150 to 250 F.

The significance of the steam treating step is illustrated in the following examples and data: 7

Steamed- Unsteamed- Example 1 (below) Example 6 (below) Sulfur, percent 1.16 3.72. Phosphorus, percent 1.57 1.65. Copper Strip, 1 hr. at 250 F. Light Peacock"-.- Black. Reaction with Water None Evolves Hi8.

dor Slight Sulturous Strong HzS. Homogeneity Clear Solids separate at room temperature.

Busting of Gear Oil Blends A B C p D Base Oils, Weight Percent:

Solvent refined neutraL Solvent refined bright stock.

Additives, Weight Percent:

Preparations of Above Gear Oil Free. Turb. Oil Peacock V H vy.

guhsis Fest, Continued to Stain.

Rust Test, Continued to 96 hours.

1 An additional 2.5 percent H20 added each 24 hours on test Thus the product of Example I shows greatly reduced amounts of rusting in typical gear oil blends by CRC L-l3 and gear oil procedure turbine oil rusting tests. Compare blends A and B in the above table to'blends C and D.

This is a very important advantage inasmuch as a major I ment. The steamed product is quite stable'in the presence of moisture compared tothe unsteamed product which gives 'off quantities of hydrogen sulfide on warming with a small amount of water. The steamed product is also clear and homogeneous compared to a definite haze and separation in the corresponding unsteamedpreparations filtered at 150 to 250 F. The steaming step is conductedat elevated temperature, e. g. about 300 F. Further finishing is unnecessary except to insure the desired degree of dehydration. Vacuum at about 300 F. or nitrogen blowing or both effectively dehydrate the concentrates. Air may be blown over the products to remove water but the process is more tedious and air exposure tends to degrade color and increase acidity. 7 I

The nature of the products and processing methods of I my invention are further illustrated in the following detailed examples of typical preparations inwhich Examples III (A), VI, and VII represent undesirable or ordinary procedures. Tests on-the base oils employed in the examples are listed in Table I below. Example I (A) A 22-liter 3-neck flask equipped with a vacuum seal stirrer and a heating mantle was charged with 12,543

. grams ofbase oil B and l27grams of diatornaceous earth filter aid. The oil was heated to 240 F. with stirring under avacuum of l-2 cm. of'r'n ercury to thoroughly dry 275 F. The temperature was raised to 400 F. over a period of 1 hour. Heating and stirring were continued at this temperature for 10.5 hours. Then the preparation was allowed to cool and stand overnight. The following day it was reheated to 250 F. and filtered into a clean 22-liter flask. Then 0.65 gram of Dow Corning Fluid 200 antifoam additive was added and the preparation reheated with stirring. Steam was introduced to the flask at a temperature of 230 F. and the temperature raised to 320 F. in 30 minutes. Steam blowing was continued at approximately this temperature for 4.0 hours. The steam was shut off and the flask gradually evacuated to a pressure of 1-2 cm. in 30 minutes. Heating was continued for an additional 30 minutes. The product was cooled to 260 F. and filtered through paper with no evidence of insolubles or acid haze. Analysis of the product showed: Acid No., 30.9; saponification No., 47.1; sulfur, 1.15 per cent; phosphorus, 1.78 per cent; 0. D. color, 1,461; copper strip 1 hour at 250 F light peacock; insolubles, none.

Example I (B) This preparation was identical with that of Example I (A). Analysis of the product showed: Acid No., 28.4; saponification No., 51.0; sulfur, 1.02 per cent; phosphorus, 1.51 per cent; 0. D. color, 1,653; insolubles, none.

Preparations of Example I (A) and example I (B) were blended in equal proportions for extensive testing and gave the following analysis: Gravity API, 20.5; acid No., 39.1; saponification No., 44.7; sulfur, 1.16 per cent; phosphorus, 1.57 per cent; 0. D. color, 1,627.

Example I] A 22-liter 3-neck flask equipped with a stirrer and a heating mantle was charged with 13,960 grams of base oil B and 1,280 grams of phosphorus pentasulfide (8.4 per cent). The mixture was heated with vigorous stirring to a temperature of 400 F. in 3 hours. Stirring was continued at this temperature for 10.5 hours and the mixture allowed to cool for 6 hours. Diatomaceous earth filter aid (127 grams) was added and the mixture filtered at 200 to 225 F. into a clean 22-liter flask. Dow Corning Fluid 200 antifoam (0.75 gram) was added and the preparation reheated With stirring. Steam was introduced into the flask at approximately 320 F. for 4 /2 hours. Then air was introduced over the stirred contents of the flask I Example 111 (A) A 5-liter 3-neck flask equipped with a vacuum seal stirrer and a heating mantle was charged with 2,580 grams of base oil B and 420 grams of phosphorus pentasulfide. Air was removed from the flask by evacuation to approximately 2 cm. mercury pressure. The contents were heated with stirring to 480 F. over a period of 2 hours. Hydrogen sulfide was evolved vigorously at temperatures over 350 F. and was vented off at atmospheric pressure. Stirring was continued at 480 F. for 18 hours and the reaction product cooled to 320 F. before mixing with 30 grams of a diatomaceous earth filter aid (Hy-Flo Supercell). The preparation was filtered at a temperature of 150 to 200 F. A pint of the reaction product at this stage analyzed: Acid No., 37.9; sulfur, 6.2 per cent; phosphorus, 3.78 per cent; copper strip 1 hour at 250 F., black.

Example III (B) The remainder of the preparation was placed in a clean flask equipped with a stirrer, heater and steam inlet tube. Approximately 0.005 per cent of Dow Corning Fluid 200 antifoam additive (0.12 gram) was added and the contents heated to 260 F. with stirring. Steam was then introduced at a rather rapid rate and the temperature increased to approximately 320 F. over a period of about 15 minutes. Steaming was continued at this temperature for 3 hours. Water was removed from the product by slowly evacuating the flask to below 5 cm. mercury pressure and stirring at 320 F. for 10 minutes. The product was allowed to cool overnight and was then reheated with 15 grams of filter aid. The product filtered at 153-220" F. rather slowly using a Buchner funnel. Analysis of the product gave: Acid No., 65.9; saponification No., 96.2; sulfur, 2.86 per cent; phosphorus, 3.92 per cent; 0. D. color, 4,830; copper strip 1 hour at 250 F., light peacock.

Example IV A 5-liter 3-neck flask equipped with a stirrer and heating mantle was charged with 2,760 grams of a propane de-asphalted dewaxed cylinder stock, base oil D. The til was heated to 210230 F. and nitrogen blown until dry. Then 240 grams of phosphorus pentasulfide was added and the mixture heated with stirring to a temperature of 400 F. over a period of approximately 2 hours. The mixture was stirred at 400 F. for 18 hours. After c Jo-ting to approximately 240 F., l per cent of filter aid was added and the mixture filtered. This filtered product was placed in a clean flask equipped with a stirrer and 0.15 gram of Dow Corning Fluid 200 antifoam was added. The mixture was heated to 320 F. and then blown with sat-11m at 320360 F. for 3 hours. The heat was shut off and dry air was passed into the flask over the surface of the stirring product until the temperature dropped to 240 F. The product was filtered through paper in a Buchner funnel. The product gave the following analy- .is: Acid No., 36; saponification No., 66.7; sulfur, 1.39

per cent; phosphorus, 1.86 per cent.

Example V A 12-liter 3-neck flask equipped with a stirrer and an electric heating mantle was charged with 6,721 grams of Pennsylvania bright stock, base oil C, and heated to 310 F. Phosphorus pentasulfide (1,094 grams) was added with stirring and the temperature raised to 440 F. over a period of 1 hour and 15 minutes. Vigorous hydrosulfide evolution occurred, gradually stopping almost completely at the end of 7 hours of digestion at approximately 440 F. Heating was continued 3 hours longer and the reaction allowed to stand for 56 hours. The preparation was then reheated to 235 F., mixed with 67 grams of filter aid (I-Iy Flo Supercell) and filtered. Tests on the product showed: Gravity, 15.9; kinematic viscosity at 130 F., 4,594; kinematic viscosity at 210 F., 144.4; acid No., 52.2; saponification No., 158; O. D. color, 2,750; sulfur, 6.91 per cent; phosphorus, 4.19 per cent (4.06 is theoretical) This preparation (3,000 grams) and Dow Corning Fluid 200 antifoarn (0.15 gram) were placed in a 5-liter flask equipped with a stirrer and steam inlet tube and heated to 250 F. Steam was blown through the mixture with stirring and the temperature raised to 320 F. over a period of 15 minutes. Steaming was continued at approximately this temperature for 4 /2 hours and the product dried by passing air into the flask above the surface of the stirring mixture for 10 minutes. Tests on the product show: Gravity, 21.1; kinematic viscosity hours and the reaction shut down for 6 hours.

steaming has a considerably better dark green cast. gives better colored blends than relative O. D. colors might indicate. Economics and available supply how ever, usually make the solvent treated Midcontinent oils commercially preferable.

. Example VI A -liter 3'-ne'ck flask equipped with a stirrer and heating mantle was charged with 3,162 grams of baseoil B and heated to 275 F. Phosphorus pentasulfide (264 grams) was added andfthe mixture heated with stirring to atemp'e'rature of 400 F. over a period of approximately 2% hours. Heating was continued at 400 F. for 10 Diatoma-- ceous earth filter aid (34 grams) was added to the preparation. It was then reheated to 235 F. and filtered. Analysis of this product showed: Gravity API, 21.1; viscosity 'SUS' at 210 F., 175; sulfur, 3.72 per. cent; phosph'orus, '1'.65 per cent; O. D. color, 1,537; copper strip 1 hour at'2'50 F., black. A heavy haze of insolubles slowly separated on standing at room temperature.

Example VII tric heating mantle was charged with 3,720 grams of base 8 r nominal clarification is 0.84 per cent indicating per cent hydrolysis to the objectionable haze.

Example VIII A 5-1iter 3-neck fi'ask equipped with a stainless steel stirrer and an electric heating mantle was charged with 2,720 grams of Pennsylvania bright stock (base oil C) and 680 gram's of phosphorus pentasulfide. The mixture was heated with stirring to 400 F. and the reaction con tinued for 36'hours. The preparation 'was filtered at ap-, proximately 250 F. The product gave: Acid No., 40.2;

'saponifi'c'ation No., 141; sulfur, 9.53 per cent; phosphorus,-

TABLE I Identity A B r C I) Crude Source Mid-Cont..-" Mid-Cont..- Penn Mid-Cont. Refining Method Solvent Solvent Solvent D easphaltin and Dewaxing, Bright Stock. Bright Stock" Cylinder Stock. 25.9 26-.3. 20.6.

Sulfur, Percent I '0 16 oil B. and 280 grams of phosphorus pentasulfide. V The temperature was raised to 320 F. over a period of approximately 1 hour and heating and stirring were conti'nued at approximately this temperature for 48 hours. Theproduct was cooled to 230 F. 40 grams of a diato maceous earth filter aid was added and the product filtered'. The total solids removed amounted to grams after Washingwith naphtha. These washed solids were hygroscopic and appeared to contain approximately 45 grams of granular unreacted phosphorus pentasulfide. filtered portion ofthe preparation was mixed with 01005 per cent of Dow. Corning Fluid 200 antifoam and reheated with stirring in a clean flask. Steam was blown through the mixture at 320 F. for 2 /2 hours. The preparatio'n was cooled. below 200 F. with stirring and allowed to settle 'for several days. A small portion of 'emul- V J 'siomfree clear waterlayer was removed and gave an acid number of 493.. A portion'of the emulsified, acid containing product was reheated with stirring to a tempera- .canted' from "the heavy acid layer and filtered through pa- .Analysis of this product showed: Acid No., 14.4;

saponific'ation ,'No., 33.4; a sulfur, 0.72 'per cent; phosphorus, 0.84 per cent. i

Calculation shows that-at least 6 per cent of the 7 per c'eritof phosphorus pentasulfide used reacted to give an.

soluble reaction product. The theoretical amount of phosphorus in'this reaction product is 11.69 per cent. The amount of phosphorus remaining after steaming and The additives and oil compositions of my invention were evaluated by a number of conventional and special- 1 y devised test methods including the following; 7

Copper strip activity (CRC L'I6445). Thislpr0- cedure is usedto determine the chemical activity toward copper. A copper strip one-half inch wide and three inches long is placed in a one-inch diameter test tube and covered with oil. The degree of discoloration of, the copper strip as well as the temperature and durati on of the test shall be recorded. The MIL-L-2105 specification requires no blackening afterone hour at 250 F.

Rust protection (CRC LI3-445).This test is intended to indicate the rust protective characteristics of V spected. Passing results must show no rust.

Modified almen (or Falex) rust test.-This test is currently an optional alternate for the CRC L2l445 rust test. This test is intended to measure the rust protective characteristics of a thin film of gear lubricants on steel bearings which have been run under R. conditions at elevated temperature and stored under conditions ofhigh. relative humidity.

This modification employs the pin and bushings from a Falcx test which has been run at a load of 5001-? for 25 minutes at a minimum 'oil temperature of 200 F. or higher depending on the frictional heat generated. The

pin and bushings are placed in individual crucibles and I drained 'for 30 minutes in an oven at a temperature of 180 P. Then they are placed under abelljar approxiinsoluble phosphorus acid mately 10 inches in diameter along side a 250 cc. Griffin beaker containing about 100 cc. of tap water. This assembly is stored at a room temperature of approximately 75 F. for 24 hours. The test specimens are then or score and indicate poor performance in Endurance or L-20 axle tests.

Gear oil procedure turbine oil rust testGOP TORT procedure A.A polished steel rod is immersed in a stirring mixture of 200 grams of gear lubricant and grams of distilled water for 24 hours at 140 F. using the ASTM turbine oil rust test apparatus.

Commercially acceptable multi-purpose gear lubricants have been found to generally show no more than light oil level. The test rod is washed in benzene at the com pletion of the test and air dried. Inspection is made under an Andrew technical service inspection light with a two power viewing lens. The areas above and below the cleaned with solvents and inspected for rust. A rating of 5 oil level are rated separately as outlined below. ten indicates no rusting and zero indicates heavy rusting l. Definite rusting below the oil level is a failure. or staining. 2. Heavy rusting above the oil level is a failure.

Ratings of 89 are considered acceptable for 3. Sludge or black precipitate in the used oil or beaker MIL-L-2105 government specification universal gear is generally cause for sample rejection.

Lubricants. l0 4. Emulsification of the used oil is noted.

T z'mken L-20 weedout procedure #3.A Timken Sludge accumulation test--modified.A l-inch by 6- machine is run 16 hours at 250 F., 200 R. P. M. and inch test tube containing 25 grams of oil and a 6-inch 198%: lever load with the test block mounted on a special length of 0.04-inch diameter copper Wire is blown with lever which reciprocates horizontally beneath the test air at the rate of 0.5 liter per hour for 120 hours at a cup a distance of 0.13 inch four times per minute. This temperature of 250 F. At the end of 120 hours the .2 arrangement produces an extremely high unit pressure ASTM naphtha insolubles in the oil and on the test tube at essentially line contact conditions. Therefore, unit are determined and recorded as the per cent sludge. The pressures do not decrease appreciably as wear on the test corrosion on the copper wire in mg. and any sludged or block increases. The test is very useful in indicating the varnished appearance of the oil and test tube are recorded relative performance of lubricants in the costly CRC L- 20 as a matter of information. axle test or similar Endurance type tests. This test ditfers from the standard ASTM test in A total wear on the test cup and block below about 50 that the immersed copper wire catalyst is only about onemg. with no evidence of score or surface fatigue has fourth as long as in the regular test and can be conbeen found to indicatelubricants which are passing or veniently removed at any time to check the corrosion. near passing in the CRC L20 axle test. Commercial Air is fed below instead of above the oil level because of hypoid gear lubricants which pass the CRC L-20 axle test the viscous nature of most gear oils and the slight aerausually give from 20 to mg. total wear on the cup and tion aiforded by the regular ASTMD 670-42T procedure. block and smooth fairly bright wear as in the L20 axle, Uncompounded Well refined mineral oils of -90 without evidence of surface fatigue. Typical S-Cl hypoid SUS viscosity at 210 F. show about 0.05 per cent sludge gear lubricants give up to 800 mg. wear and heavy ridging 30 at 120 hours. Therefore, sludge values over about 0.1

per cent can usually be attributed to pro-sludging additives.

The total per cent of naphtha insolubles should generally not be more than about 0.1 per cent if reasonably stable V. 1. oils are used unless pro-sludging additives are present. Pro-sludging additives may increase the insolubles to a substantial fraction of the additives present or as much as one or two per cent.

Test results on blends or phosphorized oils of the above rusting on the steel specimen either below or above the 40 examples are tabulated below:

TABLE II TEST RESULTS ON BLENDS OF MINERAL OlL-PHOSPHORUS SULFIDE PREPARATIONS Product of Example 1 2 3A 3B 4 5 6 Blank Base Oil-Percent P285 B'-7% B8.4% B14% B14%. D C yl GPenn B-7% W i t h o u 1:

Stock- 14%. Phospho- 8.0%. rized Oil Product. Base Oils, Weight Percent:

A 35 35 .1 36 36 38 33, B 65 65 64 64 62 67' Additives, Weight Percent:

Phosphorized. Oi] 4.0 4.0-. 2.0 2.0 4.0 Sulfurized Sperm Oil, 12% S- 4.5. .5 4.5. Olgin'inated Paraifin, 42% 4.5.

0.10. DC 0.005. Kin. Viscosity SUS 210 F 85.7 85.22. 84.9 4. 84.9. Cu Strip 1 hr. 250 F., CRO Light Pea- Light Pca- Dark Pea- Dark Pea- Light Stain.

11-16-445. cock. cock. cock. cock. Inspection 30 days Clear Clear Clear Clear Clear Clear. Timkeln L-20 Proc. #3 Weedout est: Wear, Cup and Block Total, 25.1 21.5 20.3 13.7 20.3 18.6 19.4 484.

mg. Bnrnish Bright Bright Bright Bright Bright Bright Bright Score None None None None Traces lines. Traces lines. Traces lines. H e a v il y scored. Sludge Accumulation at hrs., Modified: V Sludge, Percent 0.014 0.021 0.05 0.06 0.01 0.003 0.009 0.02. Tube Deposits, Percent-.-" 0.005 0.009 0.02 0.05 0.00 0.002 0.000 0.00.

Rust Protection:

Gear Oil Procedure Turbine Perfect Pass, Light Fail, Heavy Light film Very light Very light Fail, Heavy None.

Oil Rust Test A. gray. black. rust. 1n rust. film rust. black} ORG L-13-445 Pass, light Pass, light Fail, rust Pass, light Pass, gray Fail, loose Traces.

gray. gray. and black. blue. stain. black. Falex Rust Test 9 l 1 Turns to a rust brown coat in 24 additional hours on test.

' n ons n nr ren 1 reacting a mineral oil :bright stock with about 7 to 17% TABLE III Base on Blank L n oy y, c a. Kinemati'ViscosjtyfSUS 210 F ClfStz'rip, 1111'. @250 F., ORG Ll6:445 Timken L-ZO Proc. #3 Weedout Test:

" Wear, Cup and'Block Total, mg 7. 5 Br1ght Spore Nonem.

SAENachine @1000 3.1. M., CRC. 6..17.545 Sludge Accumulation 120 hrs., Modified:

Sludge, Percent Tube Deposits, P rcent Bust Protection:

Gear ,Oil'Proc. Turbine 011 Rust Test A CB L- Falex'Bust'T Light blue heavy 5111. I118 Gray blue Fail, 100% lightv stain. rust. V

10 Perfect.

V zdimilar tests at lever loads oi 7551 give 9.2 mg. bright smooth wear and usually scores heavily at 100# lever load.

My invention provide a valuabl mean f r mpartin extreme pressure p op mio to. miner l s- Low c read ly available, materials re emp o d- Y el s based on phosphorus pentasulfide, the'most expensive ingrediout, are improved and processing andequipment costs are minimized in contrast to previous comparable methods. The e ul ng p od c s in onju c on w h n e i n sultur and chlorine containing E. P. additives are charao c izod by capac ty to meet the high p d (CR L-19-645) and highterque .(QRC L.20545) axle tests which are intended to simulate opposite extremes of scrv- 40 ice and which are fundamental evaluation tests for MIL.- L-2105 government specification universal gear lubricants. Pro-sludging, pro-corrosive and rusting components are minimized or eliminated and useful E. P. life is extended.

I claim:

1. A steam-treated, clear, oil compatible, unneutralized reaction product of a mineral oil bright stock and about "7 to '17 per cent phosphorus pentasulfide at about 4Q0IIQ 5QO"F., from which insolubles have been separated at a temperature of about 1502 5,0 F. prior to' steam-treatment.

2. A lubricating oil composition which consi t es ntially of a mineral oil base and suflicient to impart extreme pressure characteristics of a steam-treated, clear, oil compatible, unneutralized reaction product of a mineral oil bright stock and about 7 to 17percent phosphorus pentasulfide at about 400 to 500 F., from which insolubles have been separated at a temperature of about I 150-250 F.-prior,to steam-treatment. a

Th m tho of m n ctu ing an unn utraliz d lubricating .oil extreme pressure additive which comprises phosphorus pentasulficle at about 400 to 500 F. for about 10 to 20 hours, cooling the reaction mixture to about to 250 F., separating insolublesand blowing the 'mixture with steam until only traces of hydrogen sulfide evolve. V

a 4. Aiclear, oil compatible, unneutralized organic phosphorus and sulfur containing composition which is the product prepared .by reacting a mineral oil bright stock and about :7 to 17 percent phosphorus pentasulfide at about 400 to 500 F. for about 10 to 20 hours, cooling the'reaction mixtureto about 150 to 250 F., separating insolubles and blowing the mixture with steam until only 7' traces of hydrogen sulfide evolve.

5 A lu ri ing o p iti nwhioh c n ists essential y f a m n ral 11 b s and 1 o 6 pero n ftheiunnentralr i-zio P odu pr pa d by ro ring amineral oil bright stock and about 7 to 17 per cent phosphorus pentasulfide at about 400 to 500 F. forabout 10 to 20 hours, cooling the reaction mixture to about 1 0 to250 F., separ ting insolubles and blowing the mixture with steamuntil only traces of hydrogen sulfide evolve.-

A s r u t o n l ompo it on wh ch consist essentially of a mineral oil base containing an extreme pressure additive selected from the .group consisting of T chlorinated wax, chlorinated. naphthalene, sulturiz ed sperm oil and sulfurized lard oil, and l to 6 per cent of a 1 the unneutralized product prepared by reacting a mineral oil bright stock and about 7 to 17 per cent phosphorus penta-sulfide at about 400 to 5.00 F. for about 10 to 20 'the mixture with steam until only tracesvof hydrogen sulfide evolve. I I,

8. A ri t n p sition whioh consis s e sent a y n m ne al o l b s and .1 .t 6 per centrof the nneutralized product prepared by reacting'a'mineral ,oilfbright stock and about 7 to 17 per cent phosphorous pentasulfide at about 400 to 500 for about 1019 20 hours, separating insolubles at an elevated 'atompql'fiml elevated temperature and blowing the mixture with steam until vonly traces of hydrogen sulfide evolve. 1

10. A gear lubricating oil composition which consists j "essentially of a mineral oil base containing an extreme pressure a ditive elected r nl .tl o gronn ons sting of chlorinated wax, chlorinated naphthalene, sulfurized sperm oil and sulfurized lard oil, and 1 to 6 per cent of the unneutralized product prepared by reacting a mineral oil bright stock and about 7 to 17 per cent phosphorous pentasulfide at about 400 to 500 F. for about 10 to 20 hours, separating insolubles at an elevated temperature and blowing the mixture with steam until only traces of hydrogen sulfide evolve.

References Cited in the file of this patent UNITED STATES PATENTS Valentine Aug. 9, 1938 Cohen Mar. 2, 1943 Loane et a1. Apr. 6, 1943 Loane et a1. Apr. 6, 1943 

1. A STEAM-TREATED, CLEAR, OIL COMPATIBLE, UNEUTRALIZED REACTION PRODUCT OF A MINERAL OIL BRIGHT STOCK AND ABOUT 7 TO 17 PER CENT PHOSPHORUS PENTASULFIDE AT ABOUT 400* TO 500* F., FROM WHICH INSOLUBLES HAVE BEEN SEPARATED AT A TEMPERATURE OF ABOUT 150*-250* F. PRIOR TO STEAM-TREATMENT.
 2. A LUBRICATING OIL COMPOSITION WHICH CONSISTS ESSENTIALLY OF A MINERAL OIL BASE AND SUFFICIENT TO IMPART EXTREME PRESSURE CHARACTERISTICS OF A STEAM-TREATED, CLEAR, OIL COMPATIBLE, UNNEUTRALIZED REACTION PRODUCT OF A MINERAL OIL BRIGHT STOCK AND ABOUT 7 TO 17 PERCENT PHOSPHORUS PENTASULFIDE AT ABOUT 400* TO 500* F., FROM WHICH INSOLUBLES HAVE BEEN SEPARATED AT A TEMPERATURE OF ABOUT 150*-250* F. PRIOR TO STEAM-TREATMENT. 